IconVault's Web Font Analyzer takes your @font-face CSS or a Google Fonts CSS URL and breaks it down into a clear audit: every font family, its weights and styles, font-display settings, unicode ranges with human-readable subset names like latin, latin-ext, cyrillic and devanagari, and every font file URL it loads. It also generates a ready-to-paste preload snippet for your critical fonts.

Alongside the breakdown you get honest performance tips for cutting font weight, such as subsetting and avoiding unused variants. The analysis runs fully in your browser, so your CSS is never uploaded. It is free with no signup. Note that it analyzes the CSS you paste, it cannot auto-discover the fonts a live page loads, so paste the CSS from the page you want to audit.